enforce id_prefixes?

[turbomam]

LinkML provides an id_prefixes attribute for slots. We could use this to require a user enters the link between a biosample and the EMP500 project as BIOPROJECT: PRJEB42019 by specifying

- id_prefixes
  - BIOPROJECT

[ddooley]

I think this could be enforced by a two fold validation: 1: validating that the "project" slot was a curie or URI, and syntactically met that; and then by insisting that any Curie has a prefix listed in the schema. But perhaps that is too strong a requirement? Are there other curies that don't need to be validated to that extent?